This proposal brings together a newly-established interdepartmental Cancer Prevention Center at the Harvard School of Public Health, with a newly re-energized Division of Cancer Epidemiology and Control at the Dana-Farber Cancer Institute in a broadly interdisciplinary, flexible yet well-integrated, educational program designed to train a new cadre of leaders in cancer prevention. We propose to recruit and train a total of 18 health professionals: * 3 will earn doctorates in the social and behavioral sciences * 10 will be physicians engaged in postdoctoral training , of whom 5 will study for a year and earn a masters in public health; 5 will have partial support (4 two years, 1 one year). while they work toward a doctorate in public health * 5 will be two-year postdoctoral fellows (Ph.D.) in the social and behavioral sciences Our goal is to have trainees emerge with (a) broad and deep knowledge of the state of the science of cancer prevention, (b) expertise in a specialized research area in which they will be positioned to develop new knowledge, (c) skill in policy analysis and (d) anchoring in professional networks through which they will be able continuously to update their knowledge of this evolving field. The social and behavioral scientists will be prepared to advance knowledge on the efficiency and effectiveness of alternative strategies for inducing behavior change at the individual, institutional, community, or policy levels. The physicians will be prepared for careers as clinical investigators or public health practitioners specializing in cancer prevention. The tripartite program includes: (1) curriculum: a newly-developed core course in cancer prevention, a special weekly seminar, and elective courses across a wide spectrum, from cancer biology to mass media; (2) research placements: participation in one of many ongoing research projects being conducted by program faculty; these, too, cover the spectrum from the micro to the macro; (3) field/clinical/lab placements: a "hands-on" experience in a laboratory, clinic, or community setting with a research or clinical preceptor. The program is structured for flexibility, and each trainee will have an advisor to provide guidance in the design of a relevant course of study.